• Korean Journal of Ecology and Environment
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• 제34권4호통권96호
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• pp.298-309
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• 2001

The purpose of this study was to evaluate the filtering-feeding effect of a freshwater mussel (Corbicula leana) on the phytoplankton communities in two lakes with different trophic conditions between June and September, 2000. Manipulation experiments were conducted with two treatments (the control and mussel addition), and each established in duplicate 10 l chambers. Both ambient nutrient (TN, TP) and chlorophyll-a concentrations were significantly (p<0.01) higher in Lake Ilgam than Lake Soyang. Cyanophytes (Microcystis, Oscillatoria, Lyngbya and Dactylococcopis) consistently dominated algal community in Lake llgam, while flagellated algae (Dinobryon divergence, Mallomonas, Rhodomonas) and cyanophytes (Microcystis)dominated in Lake Soyang. The net exponential death rate ($R\;=\;day^{-1}$) of total phytoplankton in the mussel treatment ranged $1.70{\sim}7.39$ and $0.38{\sim}1.64$ in Lakes Soyang and Ilgam, respectively. Mean filtering rate standardized by mussel AFDW ($ml\;mgAFDW^{1}\;h^{-1}$) was much higher in Lake Soyang ($1.70{\sim}3.06$) than in Lake Ilgam($0.24{\sim}0.88$0.24~o.88). Estimating FR per mussel, 1 mussel filtered $1.6{\sim}7.8\;l$ per day and $1.7{\sim}3.0\;l$ per day in Lakes Soyang and Ilgam, respectively. Based on tile C-flux tobiomass ratio, Corbicula leana consumed $0.8{\sim}4.4$ fold of phytoplankton standing stock in Lake Soyang, and $0.4{\sim}1.6$ fold in Lake Ilgam per day. Mussel feeding resulted in increase of SRP concentration by $30{\sim}50%$, compared with the control. The results of this study suggest that filter-feeding activity of Corbicula leana varies depending on the phytoplankton density and community composition. The high seston consumption rate of Corsicuja Jeaua even in a eutrophic lake suggests that biomanipulation approach using filter-feeding mussels can be used far wate rquality management in small eutrophic reservoirs.

• Journal of Korean Society of Forest Science
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• 제96권1호
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• pp.21-28
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• 2007

This study was conducted to investigate how the qualities of the stream water vary during the event in the regrowth and rehabilitation catchments in Yangju, Gyeonggido, from June to September 2005. During the observation periods, we sampled the stream water continuously by an auto-sampler (ISCO, 6712FR). The sampled waters were analyzed for suspended solid concentration, electrical conductivity and pH. The suspended solid concentration during the event increased concurrently with the stream flow. The peak of suspended solid concentration usually precedes the peak flow. The maximum value of suspended solid concentration was 420.89 mg/l in the event 1 at the regrowth catchment. Among the events simultaneously sampled at both catchments, the maximum values of suspended solid concentration were 212.8 mg/l and 58.24 mg/l in the event 3 at the regrowth and rehabilitation catchment respectively. The maximum value of EC in each event showed in the early stage of rising limb. EC decreased during the rising limb, and then showed minimum value at peak flow. EC gradually increased to pre-event value after minimum one. pH varied in similar pattern with EC. The maximum value of suspended solid concentration during each event was 2.8 to 4.3 times higher at the regrowth catchment than at the rehabilitation catchment. And the EC during each event was higher at the regrowth catchment than at the rehabilitation catchment. This results indicate that a disturbed forest soil during clear cutting at regrowth catchment still has been unstable.

• Journal of the Korean Society of Food Science and Nutrition
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• 제39권8호
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• pp.1087-1096
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• 2010

This study was conducted to investigate the physiological activity of extracts of fresh mushrooms. The components were extracted by hot water; subsequently, the hot-water extract was subjected to 60% ethanol precipitation to yield high-molecular-weight (HMW) and low-molecular-weight (LMW) fractions. Total polyphenol contents, $\beta$-glucan contents, electron-donating ability (EDA), superoxide dismutase (SOD)-like activity, nitrite-scavenging activity, fibrinolytic activity, nitric oxide (NO) production, and inhibition of NO production of the mushroom extracts were measured using lipopolysaccharide (LPS)-stimulated murine macrophages, RAW 264.7 cells. The extracts of Lentinus edodes (Berk.) Singer and Pleurotus ostreatus (Fr.) Kummer contained the highest levels of $\beta$-glucan (33.5% and 25.57%, respectively). Further, the LMW fractions of the Phellinus linteus contained the highest levels of polyphenols (233.23 mg/g). The EDA of LMW fractions (10 mg/mL) of the Phellinus linteus and Agaricus bisporus were 80.74% and 51.35%, respectively. Further, SOD-like activities of the LMW fractions were high as compared to those of the HMW fractions. Nitrite-scavenging activities of the LMW fractions (pH 1.2; concentration, 10 mg/mL) of the Phellinus linteus and Pleurotus ostreatus (Fr.) Kummer were 75.95% and 41.05%, respectively. The fibrinolytic activity of the LMW fractions of all mushrooms showed no enzyme activity by fibrin plate assay. The fibrinolytic activity of the extracts of Tricholoma matsutake was the greatest inhibitory activity at 60.4%. Further study revealed that the mushroom extracts exhibited anti-inflammatory effects on RAW 264.7 cells. The LMW fraction ($500\;{\mu}g/mL$) of the Phellinus linteus considerably inhibited NO production (100%).

• Progress in Medical Physics
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• 제24권1호
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• pp.76-83
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• 2013

Previous studies about effect of respiratory motion on diagnostic imaging and radiation therapy have been performed by monitoring external motions but these can not reflect internal organ motion well. The aim of this study was to develope the artificial pulmonary nodule able to perform non-invasive implantation to dogs in the thorax and to evaluate applicability of the model to respiratory motion studies on PET image acquisition and radiation delivery by phantom studies. Artificial pulmonary nodule was developed on the basis of 8 Fr disposable gastric feeding tube. Four anesthetized dogs underwent implantation of the models via trachea and implanted locations of the models were confirmed by fluoroscopic images. Artificial pulmonary nodule models for PET injected $^{18}F$-FDG and mounted on the respiratory motion phantom. PET images of those acquired under static, 10-rpm- and 15-rpm-longitudinal round motion status. Artificial pulmonary nodule models for radiation delivery inserted glass dosemeter and mounted on the respiratory motion phantom. Radiation delivery was performed at 1 Gy under static, 10-rpm- and 15-rpm-longitudinal round motion status. Fluoroscpic images showed that all models implanted in the proximal caudal bronchiole and location of models changed as respiratory cycle. Artificial pulmonary nodule model showed motion artifact as respiratory motion on PET images. SNR of respiratory gated images was 7.21. which was decreased when compared with that of reference images 10.15. However, counts of respiratory images on profiles showed similar pattern with those of reference images when compared with those of static images, and it is assured that reconstruction of images using by respiratory gating improved image quality. Delivery dose to glass dosemeter inserted in the models were same under static and 10-rpm-longitudinal motion status with 0.91 Gy, but dose delivered under 15-rpm-longitudinal motion status was decreased with 0.90 Gy. Mild decrease of delivered radiation dose confirmed by electrometer. The model implanted in the proximal caudal bronchiole with high feasibility and reflected pulmonary internal motion on fluoroscopic images. Motion artifact could show on PET images and respiratory motion resulted in mild blurring during radiation delivery. So, the artificial pulmonary nodule model will be useful tools for study about evaluation of motion on diagnostic imaging and radiation therapy using laboratory animals.

• KSCE Journal of Civil and Environmental Engineering Research
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• 제13권3호
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• pp.93-105
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• 1993

In this paper, the maximum scour depths at piers located in the Bo Cheong Stream, which is a tributary in the Geum River System, were calculated and compared using 24 local pier scour equations. The equations were classified as six groups by non-dimensional types of equations. The geometric data in the stream bed and pier data at San Seong, Yi Pyung and San Gye, which are IHP data collection stations, were utilized for applying the scour equations. The geometric data in the stream bed were obtained by analyzing the bed material sampled in three stations which are in the left side, middle and right side for stream direction. The maximum flow velocities at maximum flow depths which were measured from 1982 to 1991, were used as the hydraulic flow data. The pier data for predicting pier scour depths were measured in the fields. The maximum pier scour depths calculated using the equations were compared with the held scour depths measured in the streams or rivers in the world. Arunachalam, Shen-Karaki III, Jain-Fischer equations are selected as the proper local scour equations for predicting the maximum local scour depths at piers in the Bo Cheong Stream. Inglis-Lacey and Shen-Karaki II equations are applicable in case of rapid flows conditions in which Froude number is over 0.3. Froehlich, Laursen I, Laursen II, Neill, Melville equations are applicable in the slow flow conditions in which Froude number is less than 0.3. Blench equation or Inglis-Poona equation varies rapidly by changing Froude numbers. Therefore the equations should not be used without careful considerations in selecting the applicable ranges. The maximum local scour depths calculated using Sarma-Krishnamurthy, Ahmad, Coleman, Varzeliotis, Larras, Bata, Chitale, Venkatadri, Basik-Basamily-Ergun, U.S.G.S., Shen I equations are usually less than the scour depths measured in the fields.

• Journal of Mushroom
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• 제18권1호
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• pp.20-28
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• 2020

This study was conducted to determine the antioxidant, nitrite scavenging, melanin tyrosinase inhibitory, and melanogenesis inhibitory activities of fermented Coix lacryma-jobi L. var. mayuen Stapf. by Hericium erinaceum (Bull.: Fr.) mycelial hot water extract (FCLHE). Additionally, we analyzed β-glucan and ergosterol contents in FCLHE and C. lacryma-jobi hot water extract (CLHE). The ergosterol and β-glucan contents in FCLHE were 740.2 mg% and 245.3 mg%, respectively, whereas these components were not detected in CLHE. FCLHE showed higher cell viability than CLHE. When B16F10 cells were treated with 500 ㎍/mL each of CLHE and FCLHE, the FCLHE treated cells produced 8.9 uM nitric oxide (NO), which was lower than that produced by CLHE treated cells (10.6 uM). The FCLHE treated cells showed significantly greater tyrosinase inhibition and melanin production at all tested concentrations than when compared to the CLHE treated group. Antioxidant parameters such as DPPH and ABTS radical scavenging activities were higher in FCLHE than in CLHE. These results suggest that FCLHE can be used as a raw material for functional foods, for food additives, and in the cosmetic industry.

• Applied Biological Chemistry
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• 제49권4호
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• pp.322-327
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• 2006

Food constituents analysis of Acer tegmentosum. Maxim.(Acer TM) stem was carried out according to AOAC method, and the antiradical activity on DPPH and cytotoxicity on human cell lines (AGS, HepG2, A549, MCF-7 and Chang) for the 80% ethylalcohol(EtOH) extracts of Acer TM stem were studied. The antiradical activity on DPPH radical of the ethylacetate(EtOAc) fraction of the bark showed a higher activity than that of $\alpha$-tocopherol, ascorbic acid and BHT. The inhibition activity of the 80% EtOH extracts from Acer TM stem on human cancer cell lines by SRB assay indicated a dose-dependent growth inhibition on most human carcinoma cells. The growth inhibition rate of each human cancer cell line showed 91.3% to AGS, 75.0% to A549, 74.1% to HepG2, and 70.2% to MCF-7 cells, respectively, when the 80% EtOH extract(1 mg/ml) of Acer TM stem was added.

• Radiation Oncology Journal
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• 제13권4호
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• pp.321-330
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• 1995

Purpose : To evaluate whether the early pulmonary irradiation can prevent or decrease the pulmonary damage and contribute to improve ultimate survival in paraquat lung. Materials and Methods : From Jun. 1987 to Aug. 1993, thirty patients with paraquat poisoning were evaluated. Fourteen of these patients were received pulmonary irradiation(RT). All of the patients were managed with aggressive supportive treatment such as gastric lavage, forced diuresis, antioxidant agents and antifibrosis agents. Ingested amounts of paraquat were estimated into three groups(A : minimal 50cc). Pulmonary irradiation was started within 24 hours after admission(from day 1 to day 11 after ingestion of paraquat). Both whole lungs were irradiated with AP/PA parallel opposing fields using Co-60 teletherapy machine. A total of 10Gy(2Gy/fr. x 5days) was delivered without correction of lung density. Results : In group A, all patients were alive regardless of pulmonary irradiation and in group C, all of the patients were died due to multi-organ failure, especially pulmonary fibrosis regardless of pulmonary irradiation. However, in group B, six of 7 patients($86{\%}$) with no RT were died due to respiratory failure, but 4 of 8 patients with RT were alive and 4 of 5 patients who were received pulmonary irradiation within 4 days after ingestion of paraquat were all alive though radiological pulmonary change. One patient who refused RT after 2Gy died due to pulmonary fibrosis. All 3 patients who were received pulmonary irradiation after 4 days after ingestion were died due to pulmonary fibrosis in spite of recovery from renal and hepatic toxicity Conclusion : It is difficult to find out the effect of pulmonary irradiation on the course of the paraquat lung because the precise plasma and urine paraquat concentration were not available between control and irradiation groups. But early pulmonary irradiation within 4 days after paraquat poisoning with aggresive supportive treatment appears to decrease Pulmonary toxicity and contribute survival in patients with mouthful ingestion of paraquat who are destined to have reversible renal and hepatic damage but irreversible pulmonary toxicity.

• Korean Journal of Environmental Agriculture
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• 제27권4호
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• pp.303-313
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• 2008

This research is aimed to investigate the cultivation method of oyster mushroom[Pleurotus ostreatus (Jacq. ex Fr.) Kummer] at the non-sterilized medium with $Ca(OH)_2$ treatment. Therefore, experiments were carried out to develop non-sterilization method of medium by addition of $Ca(OH)_2$ for omission of heat sterilization progress of medium. General components, minerals and amino acid in Jiri wild type No. 1 (Pleurotus ostreatus) and production cost were analyzed. For the purpose of omission of heat sterilization progress, treatment ratio of $Ca(OH)_2$ (purity 95%) was 5%(w/w) of dry medium. Initial pH of this medium was 11 and then the pH was changed by 9 after the uniform mixing of the medium for half an hour. The various germs occurred 50% and 100% at pH 8 and pH 7 of the non-sterilized medium, respectively. Production of oyster mushroom increased by $2,030\;ton\;ha^{-1}$ when the main raw material used corn pith instead of waste cotton. The time required of mycelium culture was 30 days when hypha was cultured at the non-sterilized medium, and pinhead occurred when 2 or 3 days was passed after the time required of mycelium culture. Occurrence of pinhead was most rapid at the condition of $22{\sim}26^{\circ}C$, 65% humidity and pH $6.5{\sim}7.0$ and required of $22{\sim}28$ days at $70{\sim}80\;mm$ thickness of non-sterilized medium. Ca content in 1st harvest oyster mushroom was higher than that in 2nd harvest one, and its difference was $30.3\;mg\;kg^{-1}$. Amino acid content by stipe thickness of oyster mushroom was ranged from 411.2 to $343.9\;mg\;kg^{-1}$ both in a pileus and a stipe of 1st harvest mushroom, and from 402.4 to $498.2\;mg\;kg^{-1}$ and from 442.6 to $470.4\;mg\;kg^{-1}$ in those of 2nd harvest one, respectively. The results of the present study suggest that the non-sterilization medium by addition of $Ca(OH)_2$ is usable with the cultivation of oyster mushroom.

• Korean Journal of Ecology and Environment
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• 제41권spc호
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• pp.77-85
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• 2008

Grazing rates (GR) and pseudofaeces production (PFP) of native snail, Chinese mystery snail (Cipangopaludina chinensis malleata Reeve) on natural colonial morphs of Microcystis aeruginosa was measured. C. chinensis was collected from the upstream of the Geum River (Boryeong, Korea), where they co-habituated with Unio douglasiae and Lanceolaria acrorhyncha. The experiments were performed to evaluate the GR and PFP at different conditions such as; incubation time (1, 3, 5, 7, 9 and 11 hr), body size (3 to 6.1 cm, n=28), snail density (0.5, 1, 1.5 and 2.0 ind. $L^{-1}$) and prey concentration (168.3, 336.7, 505.0 and $673.0{\mu}g\;Chl-{\alpha}L^{-1}$). All experiments were triplicated, and conducted in transparent acrylic vessel (3L in volume). Regarding feeding time, a highest GR (0.538L $gAFDW^{-1}h^{-1}$) and PFP $(7.18mgAFDW^{-1})$ appeared at 1hr and 7hr after snail stocking, respectively. Interestingly, the snail, smaller than 4.5cm in body size, showed a wide range of GR ($-4.173{\sim}1.087L\;gAFDW^{-1}h^{-1}$) for the initial period (1 and 4hrs of stocking), compared to those greater than 4.5cm, which showed a stable FR, higher than 0.5L $gAFDW^{-1}h^{-1}$. Upon density effect, the density of 1.5 ind. $L^{-1}$ induced the most effective inhibition on Microcystis biomass with highest PFP. On the prey concentration, highest GR (0.897L $gAFDW^{-1}h^{-1}$) and PFP (3.67 mg $gAFDW^{-1}h^{-1}$) were induced at the level of $168.3{\mu}g\;Chl-{\alpha}L^{-1}$ and $673{\mu}g\;Chl-{\alpha}L^{-1}$, respectively. GR and PFP of this freshwater snail on the cyanobacterial bloom (M. aeruginosa) varied with the feeding conditions, and they were comparatively high for a short period of time less than 7hrs regardless of the stocking condition. Our results suggest that this freshwater snail has a potential to control cyanobacterial bloom when provided with suitable condition.